S-91251A895 7/8"-9 x 6 1/2" ASTM A574 Alloy Steel Socket Head Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength (170,000 psi) ensures reliable performance under extreme loads, reducing the risk of fastener failure in demanding applications.
• Superior surface protection with black-oxide coating on alloy steel resists corrosion, extending service life in harsh industrial environments.
• Precise Class 3A thread fit provides tighter tolerances for secure, vibration-resistant assemblies, minimizing loosening over time.
• High torque capability from the 3/4" hex drive and standard socket head design allows for easy installation and removal with standard tools.
• Optimized load distribution through the partially threaded design concentrates strength where needed, enhancing joint integrity.
• Consistent performance backed by Rockwell C37 hardness, ensuring durability and resistance to wear in repetitive or high-stress uses.
• Broad compatibility with 7/8"-9 UNRC coarse threads simplifies sourcing and installation in various machinery and structural applications.

Professional Applications & Engineering Value

This black-oxide alloy steel socket head cap screw is engineered to address critical challenges in heavy-duty industrial settings, such as machinery assembly, construction equipment, and automotive systems. The high tensile strength (170,000 psi) and Rockwell C37 hardness provide resilience against dynamic loads and abrasion, reducing maintenance downtime. Its partially threaded design and Class 3A thread fit ensure precise engagement, preventing thread stripping and enhancing vibration resistance in UNRC coarse thread applications. The black-oxide surface treatment offers moderate corrosion protection, making it suitable for environments where exposure to moisture or chemicals is a concern. By complying with ASTM A574, it delivers consistent quality for engineers and procurement specialists seeking reliable inch system fasteners that meet rigorous performance standards.

Specification Summary & Compliance

This socket head cap screw adheres to strict dimensional and performance criteria, including a Class 3A thread fit for superior precision and UNRC coarse threads (7/8"-9) with a minimum thread length of 2 1/4". Manufactured in accordance with ASTM A574 specifications, it ensures high-strength reliability. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming its safety and environmental responsibility for global industrial use.